I've been happy with a Dakine Duel 26L. I know that's going to seem too pedestrian to some because it's pretty inexpensive, but it fit my requirements. First,

I've been happy with a Dakine Duel 26L. I know that's going to seem too pedestrian to some because it's pretty inexpensive, but it fit my requirements. First, it had to be relatively compact. Specifically, it had to fit under a standard economy-class airplane seat with room for my big feet. Second, I wanted something more vertically oriented than usual. Most backpacks have multiple pockets in a "sandwich" configuration, so everything slumps into the bottom of each one and the top remains completely slack. I hate that. Having two decently sized outer pockets in an over/under configuration really helps. The straps (it's meant to be a skateboard pack) are occasionally handy to hold a jacket or hoodie instead of stuffing it inside. It's not as weatherproof as some, certainly not as stylish, but it has survived a dozen week-long coast-to-coast trips and still seems barely worn. I looked at a lot of camera and other packs that might satisfy my preference for verticality even better, but for one third the price this one has done just fine.